The present invention relates to an internal grinding machine, and more particularly, to an improvement of a machine for grinding a plurality of concentric inner or end surface of a workpiece by means of grinding wheels.
Applicant has proposed an internal grinding machine with reference to this multi-wheel-spindle internal grinding machine in U.S. patent application Ser. No. 325,102 in which one infeeding mechanism in a shift table is used for infeeding to multiple grinding wheels. But a suitable infeeding speed for grinding or dressing varies in response to the grinding wheel geometry, the workpiece geometry, its ground area, its expected surface finish as well as other conditions. Single infeeding mechanism is not suitable for giving a plurality of infeeding speeds as it requires complicated control.